The worst part about self hosting tools for collaboration and communication is identity management.
I don’t want to maintain your account. I just want to validate that you have an account.
But there is not an account provider I trust.
So I guess I’m back to email addresses and maintaining a password database.
There's an issue in one of the #CommonsPub repos referencing improving Oauth and looking to Indie web. I think it would be a good addition for solo instances and certain communities to be an authentication source with the caveat that instance managers may not want to turn it in for instances where there isn't some other connection between members